OF TIDE HUMAN BREED. 17
narrower and more numerous, and if the calculations had been carried on to two more places of decimals, the correspondence would have been identical to the nearest tenthousandth. It was unnecessary to take the trouble of doing this, as the table affords a sufficient basis for what I am about to say. Though it does not profess to be more than approximately true in detail, it is certainly trustworthy in its general form, including as it does the effects of regression, filial dispersion, and the equation that connects a parental generation with a filial one when they are statistically alike. Minor corrections will be hereafter required, and can be applied when we have a better knowledge of the material. In the meantime it will serve as a standard table of descent from each generation of a people to its successor.
Economy of Effort.-I shall now use the
table to show the economy of concentrating our attention upon the highest classes. We will therefore trace the origin of the V classwhich is the highest in the table. Of its 34 or 35 sons, 6 come from V parentages, io from U, io from T, 5 from S, 3 from R, and none from any class below R. But the numbers of the contributing parentages have also to be taken into account. When this is done, we see that the lower classes make their scores owing to their quantity and not to their quality ; for while 35 V-class parents